I recently fitted a Wooshbikes DWG22C 48Volt hub drive kit to a friend's ICE Trike Adventure 26" (recumbent, tadpole). My friend lives in a very hilly area and, being in his 80s, is not as strong as he once was and limited as to where he could go. He says the conversion changed hill-climbing from very hard work (grinding away in his 22T small ring) to a pleasure. Where he was climbing at 3 or 4 mph, he now does 10mph with ease.
My impressions following a decent test ride: Strong torque at low speed, pulls away effortlessly after about half a turn of the pedals. Goes up steep hills (more than 10%) like a rocket in level 3 with moderate pedalling. I mostly used levels 1 and 2 elsewhere. I can't see when levels 4 and 5 might be needed, but they are there if required. After 15 miles of up and down I still had over 80% battery left. Being a trike, it's often going over the assist speed on the level or downhill, so battery capacity is mainly reserved for hills.
I think this kit would be absolutely fine for up to 12%/1:8 and probably steeper. I didn't fit a thumb throttle. For a bit of help on a hill start, just use the walk assist and then let go once the cadence sensor kicks the motor in. Or be in the right gear in the forst place!
I ride a Cube e-bike with Bosch torque sensor, so I wasn't sure how I would find the cadence sensor system on the trike. Suffice to say, after 15 miles I got off it with a huge grin - it was great fun, especially charging up hills.
Key benefits of the rear hub motor system (compared with crank drive) are relative ease of installation and lower maintenance. there may be a reduction in performance but the hub motor was more than up to the task.
It was necessary to take care routing the cables around the folding frame hinge, the suspension pivot and the handlebars to ensure there was no undue flexing or pulling. Easily done with a bit of care. I used some cable tidy sheathing to protect the cables as well. A pair of home made trestles about 2 feet high lifted the trike to a height where it was easy to work on it. We could also turn it upside down, which was great for fitting the motor wheel and doing the cabling. (Great for routine maintenance too.)
Battery mounting was more of a challenge, but easily solved (by anyone that can use a tape measure, drill and hacksaw). Starting point is the excellent ICE Trikes battery mount (c. £88), which bolts directly to the trike - this solved most of the mounting problems. Unfortunately it is designed for Shimano batteries and is not quite long enough to accept the HL battery supplied by Wooshbikes. I obtained a strip of alloy from a metal fabricator, 200mm long x 60mm wide x 5mm thick. I bolted that to the ICE trike plate using four M5 countersunk bolts, then mounted the battery using three M5 bolts, making that sure the mounting plate did not cover the controller heat sink - apparently this can get fairly warm if the motor has to work hard for long periods, although at level 3 this may not be an issue.
I fitted a 47mm Marathon Plus tyre to the wheel supplied with the motor (25mm wide rim) in order to reduce road shocks for the wheel and motor, and to minimise risk of punctures. These tyres worked fine with the ICE Trike mudguard. It's also had the effect of improving the trike's directional stability at speed.